The present invention relates to improvements to machine control systems of the type which include a display screen and means for displaying a plurality of separate screen images on the screen.
Such machine control systems are used to control a wide variety of machines, such as for example sheet metal presses for press forming products such as sheet metal housings and automotive body components. Such presses and their component dies represent a major capital investment. Damage to either the press or the die can result in unacceptably long downtime. In addition, there is the possibility that an improperly controlled machine may injure operators or other personnel.
For all of these reasons, it is critically important that the machine control system operate as desired, and that undesired movements of the machine or movements that could result from an improper or incomplete screen being displayed be eliminated. The present invention is directed to improvements to such machine control systems which improve the reliability of the system and which can be used to place the controlled machine, if desired, under direct manual control of the operator.